Many gardeners want to grow tasty and beautiful grapes. But this plant needs special care, as well as protection from various pests and infections. Often beginners ask why grapes turn black and what to do. In this article, we will consider in more detail the causes of rotting and drying of grapes, as well as treatment and preventive measures.
Causes
If the grapes turn black, then several reasons must be considered. For example, if the vine is affected by an infectious disease, then the causative agent may be a pest, virus or fungus. In addition, special attention should be paid to the care provided. If the gardener makes mistakes during care activities, then they can also contribute to the development of various diseases.
Mechanical damage to leaves and berries, as well as the climate in which grapes grow, also affect the condition of the plant.
The fungus and virus attack the plant quite quickly, so the disease spreads very actively. Initially, small spots appear on the berries, soon they become large in diameter, in addition, the berries themselves lose their shape, darken and, as a result, dry out. It should be remembered that the plant could become infected in various ways, because spores are transferred not only from the diseased to healthy grapes. Harmful microorganisms can enter a plant with the help of water, a person or an animal.
If the green grapes turn black, then several infectious diseases should be considered.
- Downy mildew, or mildew. Usually spores overwinter in the remains of foliage, and in spring they begin to infect grapes, they are carried by the wind. Usually the berries begin to suffer first, they turn black, and then the leaves are also affected, they curl and dry out.
- Black spotting. If after the rain the berries began to turn black, then most likely this disease was the cause. If no action is taken, the disease will spread to shoots and leaves. An excellent tool is Bordeaux liquid, which is used to spray the affected areas.
- Antraknoz. Almost the entire shrub dries up with this disease. First, shoots and leaves are affected – brown spots form on them, then the disease passes to the stem. It is recommended to immediately remove and burn the affected areas, since the grapes can lose most of the foliage.
Grapes turn black not only from infectious diseases. The reason may lie in the wrong care of the plant. For example, if grapes do not receive the required amount of moisture in summer, then the berries may also turn black. It is very important to provide the grapes with the necessary watering during the growing season.
The reason may be heavy soil. If yellowish spots appear on the foliage, then this may be non-infectious chlorosis. The application of mineral fertilizers will help to solve this problem.
Treatment
After determining the cause of the appearance of black berries on the grapes, you can proceed to the treatment of the shrub. Depending on the disease, the most effective remedy is selected. For example, if mildew is the cause of black berries, the affected plants must be dug up and burned, otherwise this disease will affect all other plants. So that the grapes do not get sick with black spot, it is recommended to carry out regular preventive measures.. In this case, special fungicides will be required, they should be applied at least twice a summer. If the disease has already affected the vine, then all the affected plants should be dug up and removed, and the cut points should be treated with a disinfectant.
It is also very difficult to treat anthracnose, so it is better to spare no effort on preventive measures. During the growing season (before flowering and during the ripening of berries), it is necessary to spray shrubs. It is better to carry out the procedure after the rains so that the measures are more effective. If it is already time to harvest, then spraying is transferred and carried out after harvesting.
If diseases continue to develop in the autumn period, you need to continue the fight.
Preventive measures
It is very important to carry out preventive procedures, then blackening of grapes can be prevented. Experienced gardeners recommend paying attention to a few tips.
- From the beginning of the growing season, grapes need close attention. Carry out regular inspections of the plant, especially the leaves and clusters.
- If dried parts are noticed on the grapes, black dots or spots appear, it is worth moving on to more active actions.
- Bordeaux liquid or special preparations help to cope with many infectious diseases.
- It is recommended to remove the affected parts in a timely manner.
- For planting, you need to use only healthy planting material.
- Timely garter shoots to prevent touching the soil.
- Top dressing with balanced mineral fertilizers.
- Creating the correct shape of the vine.
All grape varieties are prone to blackening if preventive measures are not taken. But among the most resistant varieties can be distinguished such as “Italy”, “Augustin”, “Merlot”, “Black Moldavian”, “Traminer” and others. But the varieties “Pearl”, “Cardinal”, “Cabernet Sauvignon” are prone to various fungal diseases. If you notice blackening in time, determine the cause, identify the disease, then the probability of not losing the crop increases significantly. Careful control and timely processing of grapes will ensure a beautiful and tasty harvest.
